Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...
[firefly-linux-kernel-4.4.55.git] / drivers / net / pasemi_mac.c
index 5eb5e47120d07a409b869eeb8874718bc045d984..9f9a421c99b33fa4a107d4aa7f3f19160a3b51b8 100644 (file)
 #include <net/checksum.h>
 
 #include <asm/irq.h>
+#include <asm/firmware.h>
 
 #include "pasemi_mac.h"
 
+/* We have our own align, since ppc64 in general has it at 0 because
+ * of design flaws in some of the server bridge chips. However, for
+ * PWRficient doing the unaligned copies is more expensive than doing
+ * unaligned DMA, so make sure the data is aligned instead.
+ */
+#define LOCAL_SKB_ALIGN        2
 
 /* TODO list
  *
- * - Get rid of pci_{read,write}_config(), map registers with ioremap
- *   for performance
- * - PHY support
  * - Multicast support
  * - Large MTU support
- * - Other performance improvements
+ * - SW LRO
+ * - Multiqueue RX/TX
  */
 
 
 /* Must be a power of two */
-#define RX_RING_SIZE 512
-#define TX_RING_SIZE 512
+#define RX_RING_SIZE 4096
+#define TX_RING_SIZE 4096
 
 #define DEFAULT_MSG_ENABLE       \
        (NETIF_MSG_DRV          | \
@@ -85,6 +90,15 @@ MODULE_PARM_DESC(debug, "PA Semi MAC bitmapped debugging message enable value");
 
 static struct pasdma_status *dma_status;
 
+static int translation_enabled(void)
+{
+#if defined(CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE)
+       return 1;
+#else
+       return firmware_has_feature(FW_FEATURE_LPAR);
+#endif
+}
+
 static void write_iob_reg(struct pasemi_mac *mac, unsigned int reg,
                          unsigned int val)
 {
@@ -189,6 +203,7 @@ static int pasemi_mac_setup_rx_resources(struct net_device *dev)
        struct pasemi_mac_rxring *ring;
        struct pasemi_mac *mac = netdev_priv(dev);
        int chan_id = mac->dma_rxch;
+       unsigned int cfg;
 
        ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 
@@ -228,18 +243,28 @@ static int pasemi_mac_setup_rx_resources(struct net_device *dev)
                           PAS_DMA_RXCHAN_BASEU_BRBH(ring->dma >> 32) |
                           PAS_DMA_RXCHAN_BASEU_SIZ(RX_RING_SIZE >> 3));
 
-       write_dma_reg(mac, PAS_DMA_RXCHAN_CFG(chan_id),
-                          PAS_DMA_RXCHAN_CFG_HBU(2));
+       cfg = PAS_DMA_RXCHAN_CFG_HBU(2);
+
+       if (translation_enabled())
+               cfg |= PAS_DMA_RXCHAN_CFG_CTR;
+
+       write_dma_reg(mac, PAS_DMA_RXCHAN_CFG(chan_id), cfg);
 
        write_dma_reg(mac, PAS_DMA_RXINT_BASEL(mac->dma_if),
-                          PAS_DMA_RXINT_BASEL_BRBL(__pa(ring->buffers)));
+                          PAS_DMA_RXINT_BASEL_BRBL(ring->buf_dma));
 
        write_dma_reg(mac, PAS_DMA_RXINT_BASEU(mac->dma_if),
-                          PAS_DMA_RXINT_BASEU_BRBH(__pa(ring->buffers) >> 32) |
+                          PAS_DMA_RXINT_BASEU_BRBH(ring->buf_dma >> 32) |
                           PAS_DMA_RXINT_BASEU_SIZ(RX_RING_SIZE >> 3));
 
-       write_dma_reg(mac, PAS_DMA_RXINT_CFG(mac->dma_if),
-                          PAS_DMA_RXINT_CFG_DHL(2));
+       cfg = PAS_DMA_RXINT_CFG_DHL(3) | PAS_DMA_RXINT_CFG_L2 |
+             PAS_DMA_RXINT_CFG_LW | PAS_DMA_RXINT_CFG_RBP |
+             PAS_DMA_RXINT_CFG_HEN;
+
+       if (translation_enabled())
+               cfg |= PAS_DMA_RXINT_CFG_ITRR | PAS_DMA_RXINT_CFG_ITR;
+
+       write_dma_reg(mac, PAS_DMA_RXINT_CFG(mac->dma_if), cfg);
 
        ring->next_to_fill = 0;
        ring->next_to_clean = 0;
@@ -269,6 +294,7 @@ static int pasemi_mac_setup_tx_resources(struct net_device *dev)
        u32 val;
        int chan_id = mac->dma_txch;
        struct pasemi_mac_txring *ring;
+       unsigned int cfg;
 
        ring = kzalloc(sizeof(*ring), GFP_KERNEL);
        if (!ring)
@@ -298,11 +324,15 @@ static int pasemi_mac_setup_tx_resources(struct net_device *dev)
 
        write_dma_reg(mac, PAS_DMA_TXCHAN_BASEU(chan_id), val);
 
-       write_dma_reg(mac, PAS_DMA_TXCHAN_CFG(chan_id),
-                          PAS_DMA_TXCHAN_CFG_TY_IFACE |
-                          PAS_DMA_TXCHAN_CFG_TATTR(mac->dma_if) |
-                          PAS_DMA_TXCHAN_CFG_UP |
-                          PAS_DMA_TXCHAN_CFG_WT(2));
+       cfg = PAS_DMA_TXCHAN_CFG_TY_IFACE |
+             PAS_DMA_TXCHAN_CFG_TATTR(mac->dma_if) |
+             PAS_DMA_TXCHAN_CFG_UP |
+             PAS_DMA_TXCHAN_CFG_WT(2);
+
+       if (translation_enabled())
+               cfg |= PAS_DMA_TXCHAN_CFG_TRD | PAS_DMA_TXCHAN_CFG_TRR;
+
+       write_dma_reg(mac, PAS_DMA_TXCHAN_CFG(chan_id), cfg);
 
        ring->next_to_fill = 0;
        ring->next_to_clean = 0;
@@ -328,8 +358,16 @@ static void pasemi_mac_free_tx_resources(struct net_device *dev)
        struct pasemi_mac_buffer *info;
        dma_addr_t dmas[MAX_SKB_FRAGS+1];
        int freed;
+       int start, limit;
+
+       start = mac->tx->next_to_clean;
+       limit = mac->tx->next_to_fill;
 
-       for (i = 0; i < TX_RING_SIZE; i += freed) {
+       /* Compensate for when fill has wrapped and clean has not */
+       if (start > limit)
+               limit += TX_RING_SIZE;
+
+       for (i = start; i < limit; i += freed) {
                info = &TX_RING_INFO(mac, i+1);
                if (info->dma && info->skb) {
                        for (j = 0; j <= skb_shinfo(info->skb)->nr_frags; j++)
@@ -388,13 +426,12 @@ static void pasemi_mac_free_rx_resources(struct net_device *dev)
 static void pasemi_mac_replenish_rx_ring(struct net_device *dev, int limit)
 {
        struct pasemi_mac *mac = netdev_priv(dev);
-       int start = mac->rx->next_to_fill;
-       unsigned int fill, count;
+       int fill, count;
 
        if (limit <= 0)
                return;
 
-       fill = start;
+       fill = mac->rx->next_to_fill;
        for (count = 0; count < limit; count++) {
                struct pasemi_mac_buffer *info = &RX_RING_INFO(mac, fill);
                u64 *buff = &RX_BUFF(mac, fill);
@@ -407,13 +444,16 @@ static void pasemi_mac_replenish_rx_ring(struct net_device *dev, int limit)
                /* skb might still be in there for recycle on short receives */
                if (info->skb)
                        skb = info->skb;
-               else
+               else {
                        skb = dev_alloc_skb(BUF_SIZE);
+                       skb_reserve(skb, LOCAL_SKB_ALIGN);
+               }
 
                if (unlikely(!skb))
                        break;
 
-               dma = pci_map_single(mac->dma_pdev, skb->data, BUF_SIZE,
+               dma = pci_map_single(mac->dma_pdev, skb->data,
+                                    BUF_SIZE - LOCAL_SKB_ALIGN,
                                     PCI_DMA_FROMDEVICE);
 
                if (unlikely(dma_mapping_error(dma))) {
@@ -429,10 +469,10 @@ static void pasemi_mac_replenish_rx_ring(struct net_device *dev, int limit)
 
        wmb();
 
-       write_dma_reg(mac, PAS_DMA_RXCHAN_INCR(mac->dma_rxch), count);
        write_dma_reg(mac, PAS_DMA_RXINT_INCR(mac->dma_if), count);
 
-       mac->rx->next_to_fill += count;
+       mac->rx->next_to_fill = (mac->rx->next_to_fill + count) &
+                               (RX_RING_SIZE - 1);
 }
 
 static void pasemi_mac_restart_rx_intr(struct pasemi_mac *mac)
@@ -500,18 +540,19 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit)
        int count;
        struct pasemi_mac_buffer *info;
        struct sk_buff *skb;
-       unsigned int i, len;
+       unsigned int len;
        u64 macrx;
        dma_addr_t dma;
+       int buf_index;
+       u64 eval;
 
        spin_lock(&mac->rx->lock);
 
        n = mac->rx->next_to_clean;
 
-       for (count = limit; count; count--) {
-
-               rmb();
+       prefetch(RX_RING(mac, n));
 
+       for (count = 0; count < limit; count++) {
                macrx = RX_RING(mac, n);
 
                if ((macrx & XCT_MACRX_E) ||
@@ -523,38 +564,29 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit)
 
                info = NULL;
 
-               /* We have to scan for our skb since there's no way
-                * to back-map them from the descriptor, and if we
-                * have several receive channels then they might not
-                * show up in the same order as they were put on the
-                * interface ring.
-                */
+               BUG_ON(!(macrx & XCT_MACRX_RR_8BRES));
 
-               dma = (RX_RING(mac, n+1) & XCT_PTR_ADDR_M);
-               for (i = mac->rx->next_to_fill;
-                    i < (mac->rx->next_to_fill + RX_RING_SIZE);
-                    i++) {
-                       info = &RX_RING_INFO(mac, i);
-                       if (info->dma == dma)
-                               break;
-               }
+               eval = (RX_RING(mac, n+1) & XCT_RXRES_8B_EVAL_M) >>
+                       XCT_RXRES_8B_EVAL_S;
+               buf_index = eval-1;
 
-               prefetchw(info);
+               dma = (RX_RING(mac, n+2) & XCT_PTR_ADDR_M);
+               info = &RX_RING_INFO(mac, buf_index);
 
                skb = info->skb;
-               prefetchw(skb);
-               info->dma = 0;
 
-               pci_unmap_single(mac->dma_pdev, dma, skb->len,
-                                PCI_DMA_FROMDEVICE);
+               prefetch(skb);
+               prefetch(&skb->data_len);
 
                len = (macrx & XCT_MACRX_LLEN_M) >> XCT_MACRX_LLEN_S;
 
                if (len < 256) {
-                       struct sk_buff *new_skb =
-                           netdev_alloc_skb(mac->netdev, len + NET_IP_ALIGN);
+                       struct sk_buff *new_skb;
+
+                       new_skb = netdev_alloc_skb(mac->netdev,
+                                                  len + LOCAL_SKB_ALIGN);
                        if (new_skb) {
-                               skb_reserve(new_skb, NET_IP_ALIGN);
+                               skb_reserve(new_skb, LOCAL_SKB_ALIGN);
                                memcpy(new_skb->data, skb->data, len);
                                /* save the skb in buffer_info as good */
                                skb = new_skb;
@@ -563,10 +595,9 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit)
                } else
                        info->skb = NULL;
 
-               /* Need to zero it out since hardware doesn't, since the
-                * replenish loop uses it to tell when it's done.
-                */
-               RX_BUFF(mac, i) = 0;
+               pci_unmap_single(mac->dma_pdev, dma, len, PCI_DMA_FROMDEVICE);
+
+               info->dma = 0;
 
                skb_put(skb, len);
 
@@ -586,11 +617,29 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit)
                RX_RING(mac, n) = 0;
                RX_RING(mac, n+1) = 0;
 
-               n += 2;
+               /* Need to zero it out since hardware doesn't, since the
+                * replenish loop uses it to tell when it's done.
+                */
+               RX_BUFF(mac, buf_index) = 0;
+
+               n += 4;
+       }
+
+       if (n > RX_RING_SIZE) {
+               /* Errata 5971 workaround: L2 target of headers */
+               write_iob_reg(mac, PAS_IOB_COM_PKTHDRCNT, 0);
+               n &= (RX_RING_SIZE-1);
        }
 
        mac->rx->next_to_clean = n;
-       pasemi_mac_replenish_rx_ring(mac->netdev, limit-count);
+
+       /* Increase is in number of 16-byte entries, and since each descriptor
+        * with an 8BRES takes up 3x8 bytes (padded to 4x8), increase with
+        * count*2.
+        */
+       write_dma_reg(mac, PAS_DMA_RXCHAN_INCR(mac->dma_rxch), count << 1);
+
+       pasemi_mac_replenish_rx_ring(mac->netdev, count);
 
        spin_unlock(&mac->rx->lock);
 
@@ -603,27 +652,33 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit)
 static int pasemi_mac_clean_tx(struct pasemi_mac *mac)
 {
        int i, j;
-       struct pasemi_mac_buffer *info;
-       unsigned int start, descr_count, buf_count, limit;
+       unsigned int start, descr_count, buf_count, batch_limit;
+       unsigned int ring_limit;
        unsigned int total_count;
        unsigned long flags;
        struct sk_buff *skbs[TX_CLEAN_BATCHSIZE];
        dma_addr_t dmas[TX_CLEAN_BATCHSIZE][MAX_SKB_FRAGS+1];
 
        total_count = 0;
-       limit = TX_CLEAN_BATCHSIZE;
+       batch_limit = TX_CLEAN_BATCHSIZE;
 restart:
        spin_lock_irqsave(&mac->tx->lock, flags);
 
        start = mac->tx->next_to_clean;
+       ring_limit = mac->tx->next_to_fill;
+
+       /* Compensate for when fill has wrapped but clean has not */
+       if (start > ring_limit)
+               ring_limit += TX_RING_SIZE;
 
        buf_count = 0;
        descr_count = 0;
 
        for (i = start;
-            descr_count < limit && i < mac->tx->next_to_fill;
+            descr_count < batch_limit && i < ring_limit;
             i += buf_count) {
                u64 mactx = TX_RING(mac, i);
+               struct sk_buff *skb;
 
                if ((mactx  & XCT_MACTX_E) ||
                    (*mac->tx_status & PAS_STATUS_ERROR))
@@ -633,19 +688,15 @@ restart:
                        /* Not yet transmitted */
                        break;
 
-               info = &TX_RING_INFO(mac, i+1);
-               skbs[descr_count] = info->skb;
+               skb = TX_RING_INFO(mac, i+1).skb;
+               skbs[descr_count] = skb;
 
-               buf_count = 2 + skb_shinfo(info->skb)->nr_frags;
-               for (j = 0; j <= skb_shinfo(info->skb)->nr_frags; j++)
+               buf_count = 2 + skb_shinfo(skb)->nr_frags;
+               for (j = 0; j <= skb_shinfo(skb)->nr_frags; j++)
                        dmas[descr_count][j] = TX_RING_INFO(mac, i+1+j).dma;
 
-
-               info->dma = 0;
                TX_RING(mac, i) = 0;
                TX_RING(mac, i+1) = 0;
-               TX_RING_INFO(mac, i+1).skb = 0;
-               TX_RING_INFO(mac, i+1).dma = 0;
 
                /* Since we always fill with an even number of entries, make
                 * sure we skip any unused one at the end as well.
@@ -654,7 +705,7 @@ restart:
                        buf_count++;
                descr_count++;
        }
-       mac->tx->next_to_clean = i;
+       mac->tx->next_to_clean = i & (TX_RING_SIZE-1);
 
        spin_unlock_irqrestore(&mac->tx->lock, flags);
        netif_wake_queue(mac->netdev);
@@ -665,7 +716,7 @@ restart:
        total_count += descr_count;
 
        /* If the batch was full, try to clean more */
-       if (descr_count == limit)
+       if (descr_count == batch_limit)
                goto restart;
 
        return total_count;
@@ -880,19 +931,32 @@ static int pasemi_mac_open(struct net_device *dev)
 
        /* enable rx if */
        write_dma_reg(mac, PAS_DMA_RXINT_RCMDSTA(mac->dma_if),
-                          PAS_DMA_RXINT_RCMDSTA_EN);
+                          PAS_DMA_RXINT_RCMDSTA_EN |
+                          PAS_DMA_RXINT_RCMDSTA_DROPS_M |
+                          PAS_DMA_RXINT_RCMDSTA_BP |
+                          PAS_DMA_RXINT_RCMDSTA_OO |
+                          PAS_DMA_RXINT_RCMDSTA_BT);
 
        /* enable rx channel */
        write_dma_reg(mac, PAS_DMA_RXCHAN_CCMDSTA(mac->dma_rxch),
                           PAS_DMA_RXCHAN_CCMDSTA_EN |
-                          PAS_DMA_RXCHAN_CCMDSTA_DU);
+                          PAS_DMA_RXCHAN_CCMDSTA_DU |
+                          PAS_DMA_RXCHAN_CCMDSTA_OD |
+                          PAS_DMA_RXCHAN_CCMDSTA_FD |
+                          PAS_DMA_RXCHAN_CCMDSTA_DT);
 
        /* enable tx channel */
        write_dma_reg(mac, PAS_DMA_TXCHAN_TCMDSTA(mac->dma_txch),
-                          PAS_DMA_TXCHAN_TCMDSTA_EN);
+                          PAS_DMA_TXCHAN_TCMDSTA_EN |
+                          PAS_DMA_TXCHAN_TCMDSTA_SZ |
+                          PAS_DMA_TXCHAN_TCMDSTA_DB |
+                          PAS_DMA_TXCHAN_TCMDSTA_DE |
+                          PAS_DMA_TXCHAN_TCMDSTA_DA);
 
        pasemi_mac_replenish_rx_ring(dev, RX_RING_SIZE);
 
+       write_dma_reg(mac, PAS_DMA_RXCHAN_INCR(mac->dma_rxch), RX_RING_SIZE>>1);
+
        flags = PAS_MAC_CFG_PCFG_S1 | PAS_MAC_CFG_PCFG_PE |
                PAS_MAC_CFG_PCFG_PR | PAS_MAC_CFG_PCFG_CE;
 
@@ -964,7 +1028,7 @@ out_rx_resources:
 static int pasemi_mac_close(struct net_device *dev)
 {
        struct pasemi_mac *mac = netdev_priv(dev);
-       unsigned int stat;
+       unsigned int sta;
        int retries;
 
        if (mac->phydev) {
@@ -975,6 +1039,26 @@ static int pasemi_mac_close(struct net_device *dev)
        netif_stop_queue(dev);
        napi_disable(&mac->napi);
 
+       sta = read_dma_reg(mac, PAS_DMA_RXINT_RCMDSTA(mac->dma_if));
+       if (sta & (PAS_DMA_RXINT_RCMDSTA_BP |
+                     PAS_DMA_RXINT_RCMDSTA_OO |
+                     PAS_DMA_RXINT_RCMDSTA_BT))
+               printk(KERN_DEBUG "pasemi_mac: rcmdsta error: 0x%08x\n", sta);
+
+       sta = read_dma_reg(mac, PAS_DMA_RXCHAN_CCMDSTA(mac->dma_rxch));
+       if (sta & (PAS_DMA_RXCHAN_CCMDSTA_DU |
+                    PAS_DMA_RXCHAN_CCMDSTA_OD |
+                    PAS_DMA_RXCHAN_CCMDSTA_FD |
+                    PAS_DMA_RXCHAN_CCMDSTA_DT))
+               printk(KERN_DEBUG "pasemi_mac: ccmdsta error: 0x%08x\n", sta);
+
+       sta = read_dma_reg(mac, PAS_DMA_TXCHAN_TCMDSTA(mac->dma_txch));
+       if (sta & (PAS_DMA_TXCHAN_TCMDSTA_SZ |
+                     PAS_DMA_TXCHAN_TCMDSTA_DB |
+                     PAS_DMA_TXCHAN_TCMDSTA_DE |
+                     PAS_DMA_TXCHAN_TCMDSTA_DA))
+               printk(KERN_DEBUG "pasemi_mac: tcmdsta error: 0x%08x\n", sta);
+
        /* Clean out any pending buffers */
        pasemi_mac_clean_tx(mac);
        pasemi_mac_clean_rx(mac, RX_RING_SIZE);
@@ -985,33 +1069,33 @@ static int pasemi_mac_close(struct net_device *dev)
        write_dma_reg(mac, PAS_DMA_RXCHAN_CCMDSTA(mac->dma_rxch), PAS_DMA_RXCHAN_CCMDSTA_ST);
 
        for (retries = 0; retries < MAX_RETRIES; retries++) {
-               stat = read_dma_reg(mac, PAS_DMA_TXCHAN_TCMDSTA(mac->dma_txch));
-               if (!(stat & PAS_DMA_TXCHAN_TCMDSTA_ACT))
+               sta = read_dma_reg(mac, PAS_DMA_TXCHAN_TCMDSTA(mac->dma_txch));
+               if (!(sta & PAS_DMA_TXCHAN_TCMDSTA_ACT))
                        break;
                cond_resched();
        }
 
-       if (stat & PAS_DMA_TXCHAN_TCMDSTA_ACT)
+       if (sta & PAS_DMA_TXCHAN_TCMDSTA_ACT)
                dev_err(&mac->dma_pdev->dev, "Failed to stop tx channel\n");
 
        for (retries = 0; retries < MAX_RETRIES; retries++) {
-               stat = read_dma_reg(mac, PAS_DMA_RXCHAN_CCMDSTA(mac->dma_rxch));
-               if (!(stat & PAS_DMA_RXCHAN_CCMDSTA_ACT))
+               sta = read_dma_reg(mac, PAS_DMA_RXCHAN_CCMDSTA(mac->dma_rxch));
+               if (!(sta & PAS_DMA_RXCHAN_CCMDSTA_ACT))
                        break;
                cond_resched();
        }
 
-       if (stat & PAS_DMA_RXCHAN_CCMDSTA_ACT)
+       if (sta & PAS_DMA_RXCHAN_CCMDSTA_ACT)
                dev_err(&mac->dma_pdev->dev, "Failed to stop rx channel\n");
 
        for (retries = 0; retries < MAX_RETRIES; retries++) {
-               stat = read_dma_reg(mac, PAS_DMA_RXINT_RCMDSTA(mac->dma_if));
-               if (!(stat & PAS_DMA_RXINT_RCMDSTA_ACT))
+               sta = read_dma_reg(mac, PAS_DMA_RXINT_RCMDSTA(mac->dma_if));
+               if (!(sta & PAS_DMA_RXINT_RCMDSTA_ACT))
                        break;
                cond_resched();
        }
 
-       if (stat & PAS_DMA_RXINT_RCMDSTA_ACT)
+       if (sta & PAS_DMA_RXINT_RCMDSTA_ACT)
                dev_err(&mac->dma_pdev->dev, "Failed to stop rx interface\n");
 
        /* Then, disable the channel. This must be done separately from
@@ -1088,19 +1172,14 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev)
 
        spin_lock_irqsave(&txring->lock, flags);
 
-       if (RING_AVAIL(txring) <= nfrags+3) {
-               spin_unlock_irqrestore(&txring->lock, flags);
-               pasemi_mac_clean_tx(mac);
-               pasemi_mac_restart_tx_intr(mac);
-               spin_lock_irqsave(&txring->lock, flags);
-
-               if (RING_AVAIL(txring) <= nfrags+3) {
-                       /* Still no room -- stop the queue and wait for tx
-                        * intr when there's room.
-                        */
-                       netif_stop_queue(dev);
-                       goto out_err;
-               }
+       /* Avoid stepping on the same cache line that the DMA controller
+        * is currently about to send, so leave at least 8 words available.
+        * Total free space needed is mactx + fragments + 8
+        */
+       if (RING_AVAIL(txring) < nfrags + 10) {
+               /* no room -- stop the queue and wait for tx intr */
+               netif_stop_queue(dev);
+               goto out_err;
        }
 
        TX_RING(mac, txring->next_to_fill) = mactx;
@@ -1119,8 +1198,8 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev)
        if (nfrags & 1)
                nfrags++;
 
-       txring->next_to_fill += nfrags + 1;
-
+       txring->next_to_fill = (txring->next_to_fill + nfrags + 1) &
+                               (TX_RING_SIZE-1);
 
        dev->stats.tx_packets++;
        dev->stats.tx_bytes += skb->len;